USGS Professional Paper 1697 - Alaska Resources Library

Bulkley Metallogenic Belt of Porphyry Cu-Mo
and Polymetallic Vein Deposits (Belt BK), Central
British Columbia
The Bulkley metallogenic belt of porphyry Cu-Mo and
polymetallic vein deposits (fig. 103; tables 3, 4) occurs in central
British Columbia and is hosted in a belt of small stocks and
batholiths of the Late Cretaceous Bulkley Plutonic Suite that
are exposed along the uplift of the Skeena Arch in the central
part of the Stikinia terrane (Carter, 1982; Mihalynuk, 1992;
Mihalynuk and others, 1999). This suite is part of the extensive
Late Cretaceous and early Tertiary Coast-North Cascade
plutonic belt, which occurs along the western and central parts
Map
3,000 m
2,000
1,000
0
A
Stephens
West Ridge Fault
Cross section
West Ridge
Fault
Late Cretaceous and Early Tertiary Metallogenic Belts (84 to 52 Ma) (figs. 102, 103) 251
Fault
A
B
North Ridge
Bear Meadow
Quartz
Hill
South Saddle
South Saddle Quartz Hill Bear Meadow
76
Stephens
Fault
of the Canadian Cordillera for several thousand km (Nokleberg
and others, 1994c, 1997c; Monger and Nokleberg, 1996).
The significant porphyry Cu-Mo deposits of the Bulkley
metallogenic belt are associated with generally small, calc-alkaline
plutons of the Bulkley Plutonic Suite and consist mainly
of biotite and hornblende granodiorite and quartz diorite that
were emplaced at high levels along high-angle faults within
an extensional stress field (Dawson and others, 1991). Most
of the plutons hosting this metallogenic belt are too small to
depict on figure 103. The significant deposits in the belt are
(table 4) (Nokleberg and others 1997a,b, 1998): porphyry Cu-
Mo and Mo deposits at Glacier Gulch (Hudson Bay Mountain),
Huckleberry, and Poplar, and polymetallic vein deposits
at Red Rose, Capoose Lake, and Nadina (Silver Queen).
76
0 900 m
North Ridge
B
Intermediate dike
Late granite body
Porphyritic quartz
latite
Quartz Hill granite
body
Super breccia
Travis granite body
or stock
Coast Range
batholith
Paragneiss (Paleozoic and
Mesozoic)
Zone averaging 0.13 percent MoS
(approximate cutoff 0.05 percent) 2
Cretaceous
Contact
Tertiary
Fault, locally showing strike
dip, and sense of displacement
Figure 119. Quartz Hill porphyry Mo deposit, Central-southeastern Alaska metallogenic belt, southeastern Alaska. Schematic
map and cross section. Adapted from and Nokleberg and others (1995). See figure 103 and table 4 for location.